SEOUL, South Korea — Hundreds of Korean family members separated for more than half a century by the Korean War embraced each other in tearful reunions Saturday, a day after troops exchanged gunfire in the Demilitarized Zone dividing the countries.

SEOUL, South Korea — Hundreds of Korean family members separated for more than half a century by the Korean War embraced each other in tearful reunions Saturday, a day after troops exchanged gunfire in the Demilitarized Zone dividing the countries.

"I thought you were dead. Mother missed you so much," 61-year-old South Korean Lee Min-gwan told his 90-year-old North Korean father, Ri Jong Ryol, according to pool reports by local reporters.

"I did not forget (you) every single day for the past 60 years," Ri replied to his son, who was 100 days old when they were separated during the war.

Foreign media were not allowed to cover the reunions.

Lee was among 436 South Koreans who traveled by bus to North Korea's Diamond Mountain resort Saturday to take part in the three-day reunions with about 100 North Korean relatives.

The event is the first in a two-part series of reunions. On Wednesday, about 200 North Koreans are to begin similar three-day reunions with their South Korean relatives at the same resort.

Millions of Korean families were separated after the Korean peninsula's division in 1945 and the 1950-53 Korean War.

The reunions are emotional for Koreans, as most participants are elderly and are eager to see loved ones before they die. More than 20,800 family members have had brief reunions in face-to-face meetings or by video since a landmark inter-Korean summit in 2000. There are no mail, telephone or e-mail exchanges between ordinary citizens across the heavily fortified border.

The North Koreans told their South Korean relatives that they have led a "worthwhile life," saying all North Koreans "have formed a big harmonious family under the care of leader Kim Jong Il," North Korea's official Korean Central News Agency reported.

North Korea proposed the reunions — the first in more than a year — in an apparent conciliatory move after tensions flared over the sinking of a South Korean warship. An international investigation concluded that a North Korean torpedo sank the ship, killing 46 South Korean sailors. North Korea, however, denies involvement.

North Korea has also freed the crew of a South Korean fishing boat seized in August. In an apparent response to its overtures, South Korea sent 5,000 tons of rice to North Korea this past week as part of 10 billion won ($8.5 million) in pledged flood aid.

However, in an abrupt reversal Friday of the apparent thaw in tensions, North Korea fired two rounds at a South Korean guard post in the Demilitarized Zone and South Korean troops immediately fired back. No injuries were reported, and the reason for the attack was unclear.

The shooting came just hours after North Korea threatened to retaliate for South Korea's refusal last week to hold military talks.

The U.S.-led U.N. Command — which oversees the armistice that ended the Korean War — is considering launching an investigation of the incident, a command official said on condition of anonymity because a final decision had not been made.

The exchange highlighted the security challenges South Korea faces as it prepares to host next month's Group of 20 summit in Seoul, just 30 miles (50 kilometers) from the border.

U.S. Secretary of State Hillary Rodham Clinton asked China on Saturday to use its influence with North Korea to keep it from taking any provocative actions ahead of the summit. Clinton made the request to Chinese Foreign Minster Yang Jiechi on the sidelines of a summit of East Asian leaders in Vietnam.

Communist North Korea has a track record of provocations against South Korea at times of internal change, external pressure or when world attention is focused on Seoul.

In 1987, a year before Seoul hosted the Summer Olympics, North Korean agents planted a bomb on a South Korean plane, killing all 115 people on board. In 2002, when South Korea was jointly hosting soccer's World Cup along with Japan, a North Korean naval boat sank a South Korean patrol vessel near their disputed western sea border.